Steam-heated die fqr vulcanizing rubber belting



(No o Y Y I 2 Sheets-Sheet 1r R.v M. BASSBTT.

Steam Heated Diefor Vu-l a ni'z ing Rubber Bel-ting, No.v236,294. PatentedJamA, 1881.

(No Model. 2 Shana-Sheet}.

} R. M. BASSETT. Steam Heated Die for Vuloan-izing Rubber Belting. N6. 236,294. Patented Jan.. 4,"188l.

Ioooomooooo'ooo 20 art. accomplished by subjecting the belt to a 1: AWN? Fries.

STEAM-HEATED DlE FQR vuu.

SPEOIFIGATIQN forming part of Letters P CANlZlNG RUBBER .BELTING.

atent No. 236,294, dated January 4, 1881.

Application filed November 12, 1880. (No model.)

To all whom it may concern:

Be it known that I, ROYAL M. BAssETT, of Birmingham, in the county of New Haven and State of Connecticut, have invented certain 5 new and useful Improvementsin Steam-Heated Dies for Vulcanizing Rubber Belting; and I do hereby declare that the following is a'full and exact description thereof, reference being had to the accompanying drawings making 10 part oi this application. 7

My invention relates to a novel mode of construction or method of making such dies as are usually cast hollow, of large size, and adapted to be heated by steam. The main present uses r 5 of such dies are in the manufacture of rubber belting, in which case they are employed (in hydraulic and other presses)to press and cure the material composing the belt, which effects are, as is well known to those skilled in the high degree of pressure and holding it in this condition for some little time (usually fifteen minutes, more or less) between the highlypolished and steam-heated surfaces of the dies. The cast-iron hollow dies for such purposes vary in size, but are necessarily very large and heavy castings, usually weighing from five to seven tons, and varying in size from four feet wide by twenty long for the working-face of 0 the die to somewhat larger and smaller sizes. I have made them lately four feet wide by twenty-five feet long.

It has been customary previous to my invention, in the construction or manufacture of 3 5 large hollow cast-iron dies adapted to contain steam (to keep them hot) during their use in the hydraulic or other press in which such dies are employed, to cast such dies in one piece, cored out, so as to form the necessary hollow 4o chamber or chambers within the die for the reception and retention of the steam or other heating medium. WVith this construction of such dies and the heretofore practiced method of manufacture, not only does it become neces- 5 sary to provide a separate heavy casting as the follower or platen of the press for each such die, and to also plane and properly fit together the entire adjacent surfaces of each die and press-platen, all of which involves a very considerable expense in labor and material and renders the whole machine very heavy; but great practical difficulties are encountered in casting the dies properly and perfectly removing the cores, so that a large proportion of these immense castings are spoiled in the process of casting, since they cannot be finished up with that degree of perfection that is indispensable to the die-surface for the designed purposes thereof. These dies, as heretofore made, weigh from one to seven tons or more, while the casting for a press platen or follower to correspond weighs about from twenty-five to thirty per cent. less; and it is quite common to have about half of the hollow die-castin gs spoiled, (by reason of the necessity to core them out,) and so blown and imperfect after pouring that they have tobe thrownaway, either at the start or after an attempt to finish them up develops defects not at first discovered in the casting and caused by the coring of the chamber. When the castings possess the requisite degree of perfection to be finished up and used, the extraction from the interior of the die of the material employed to form the cores through numerous small holes left for that purpose necessitates a degree of labor and trouble which it would, of course, be very desirable to avoid, and besides this all these holes have subsequently to be tapped out and plugged up steam-tight (with screw-plugs) before the interior hollow space of the die can be utilized for its designed purpose, all of which, of course, involves more or less expense in the production of the die without any beneficial result, but rather, on the contrary, tends to render the die more or less imperfect.

I propose by my improved construction of die and different method of casting the same to avoid the spoiling of the castings and all the labor of extracting any core material through inconveniently small openings, and at the same time produce a better die, and one which, if deemed expedient, can have one of its parts serve also as a platen or follower of the press in which the die is to be used.

To these ends and objects, principally, my invention consists in a cast-iron hollow die (adapted to the usual purposes of heavy steamheated dies) composed of two separate castings made without coring, and subsequently bolted together to form the die, all as will be hereinafter more fully explained; and my in- .vention further consists in a two-part hollow cast die adapted to the purposes of steamheated dies, and having one of its parts adapted to constitute aplaten or follower of the press in which the die may be designed for use, all as will be hereinafter more fully described.

To enable those skilled in the art to make and use my improved dies, I will now proceed to more fully explain the construction and operation thereof by reference to the accompanying drawings, forming part of this specification, and in which I have shown, at-

Figure 1,in end elevation, a hydraulic press such as usually employed in the manufacture of rubber belting, and provided with steamheated dies of the ordinary construction, made according to the method of manufacture practiced heretofore. At Fig. 2 I have shown, in partial vertical section, the same press, but provided with diesmade according to my invention. Fig.3 is a detail top view (reduced scale) of the lower platen or follower, and Fig. 4 is a bottom view (same scale) of the lower hollow die-plate.

In the several figures the same parts will be found designated by the same letters of reference.

At A B O are shown the main parts of a 11ydraulic press such as usually employed in pressing and curing large rubber belts, and which I need not more particularly describe here. At Fig.1 this press is shown as provided at D and E with hollow steam-heated dies of the construction used prior to my inventi0n,in which, as illustrated, (and as those skilled in the art perfectly understand,) each die is or st in one piece, but hollow, with a series of chambers, the cores to form which chambers have all to be broken up and extracted through numerous small holes, all of which have subsequently to be tapped and plugged up, as shown at f, in the manner and for the purpose well known, and each of the dies D and E has its entire back surface planed and fitted to the face of the follower or platen (G and H) to which it is secured, and by which it is either held or moved, according to whether it be the stationary or the moving die of the press.

At Figs. 3, 4, and 5 is illustrated my improved construction of die, shown, by preference, in that form of my invention in which one of the parts of the die serves also as one of the platens of the press. In these figures, I represents the lower and moving platen, or the follower of the press, and, together with the dish-shaped casting J, forms the lower hollow steamheated die.

As clearly shown, the top surface of platen I is cast with depressions at -i, leaving those portions of the surface which are designed to be planed ott'and titted to the casting J enough higher to permit the ready treatment of such portions only in the planer in the manner common in the art in cases where castings are to be planed and bolted together.

The casting J, as shown, is dish-shaped and formed with a flange, k, around its perimeter, and has ribs 1, which are adapted to come in contact at their edges with the planed portions of plate I, and which operate to give therequisite strength to the hollow castings when put together, as shown at Fig. 2, to form the die of the machine.

The castings I and J are secured together firmly by bolts m in a well-known manner, and so, of course, that a perfectly steam-tight joint is formed between the base of the flange is and the upper side of plate I.

The working-face of the die-casting J is tinished up in the ordinary manner, and the interior of the die is supplied with steam in the usual way.

The operation of the dies made according to my invention is substantially the same as that of the old-iashioned dies cast in one piece, as hereinbetore explained. The improved dies, however, not only can be produced at far less cost, with greater perfection of the workingfaces, but with less weight of metal in proportion to a given degree of strength, and when made, as shown with reference to the lower die at Fig. 2, with one part of the dieforming also the press-platen, a vast reduction in weight of the whole machine and a large saving in the cost; of construction are effected. If, on the other hand, the die be made of two parts, according to the first part of my invention only, with the platen separate and independent of the die-castings, as shown of the upper die at Fig. 2, while the saving and advantage last alluded to will not be gained, the other and main results and advantages of my invention will, of course, be gained. Therefore both features of my invention, it will be observed, need not be embraced in a machine in order to gain the most important of the novel results and advantages I have accomplished, since by the use of the first part only of my invention may be saved the expense now caused by the imperfection of the castings of hollow dies made in one piece and a much bettersteanrheated die at't'orded for use at less cost than heretofore.

It will be understood that in the construction of machines such as the presses used for pressing and curing large rubber belts, and each of which often weighs from forty to fifty tons, the reduction of the weight by several tons is often, in many respects, quite a desideratum, and that therefore, while the greatest advantages result from the first part only of my invention, those due to the second part are by no means of an inconsiderable nature. I however wish it to be understood that the two parts of my invention are separable, and also that variations may, of course, be made in the details of construction as to either feature of my invention without departing therefrom, so long the described principles of construction and mode of operation are not materially changed.

Having so fully explained the nature and advantages of my invention as to make the 2. A hollow east-iron die adapted to conlatter clear, and so described it that one skilled tain steam for the purposes described, and in the art to which it pertains can make and composed of two castings, one of which is 15 use a machine embracing its features, either adapted to form also a platen of the press in 5 in whole or in part, what I claim as new, and I which such die is designed to work, substandesire to secure by Letters Patent, is tially as set forth.

1. A hollow east die adapted to be used for In witness whereof I have hereunto set my the usual purposes of steam-heated dies, comhand.

posed of two or more separate castings, each ROYAL M. BASSETT. IO made without coring and subsequently secured In presence oftogether, all substantially in the manner set THOS. S. BIRDSEY,

forth. EDWIN HALLOGK. 

